Disodium 5'-ribonucleotides, E number E635, is a flavor enhancer which is synergistic with glutamates in creating the taste of umami. It is a mixture of disodium inosinate (IMP) and disodium guanylate (GMP) and is often used where a food already contains natural glutamates (as in meat extract) or added monosodium glutamate (MSG). It is primarily used in flavored noodles, snack foods, chips, crackers, sauces and fast foods. It is produced by combining the sodium salts of the natural compounds guanylic acid (E626) and inosinic acid (E630).
Guanylates and inosinates are animal derived (they are produced either from meat or from fish).
A mixture of 98% monosodium glutamate and 2% E635 has four times the flavor enhancing power of monosodium glutamate (MSG) alone.
It is recommended that no food containing disodium ribonucleotides should be consumed by gout and asthma sufferers/patients.[medical citation needed] However, the concentrations used are generally so that no effects are to be expected.
Guanylates and inosinates are generally produced from meat or partly from fish. They are thus not suitable for vegans and vegetarians, and in most cases not suitable for Jews, Muslims and Hindus, depending on the origin of the product.